Abstract
An alternate routing algorithm requires a set of predetermined routing paths for each sourcedestination pair. To reduce the connection blocking probability, it is desirable that the predetermined routing paths between each source-destination pair be link-disjoint. The predetermined routing paths used in previous works on alternate routing are the k-shortest paths in terms of hop count. However, depending on the traffic requirements of all source-destination pairs, hop count based k-shortest paths may not be the best choice for the predetermined routing paths. This thesis proposes a method to find a set of link-disjoint routing paths for each sourcedestination pair to be used by an alternate routing algorithm in order to reduce the connection blocking probability. The key idea is to utilize the routing paths that are used by the optimal traffic pattern in the network. Then, for each source-destination pair, we select a set of link-disjoint routing paths from the routing paths that are used by the optimal traffic pattern such that the selected set of link-disjoint routing paths carries the most of the traffic between the source-destination pair. Simulations are performed to compare the performance of two alternate routing algorithms that use the link-disjoint routing paths found by the proposed method as the predetermined routing paths and those of the same alternate routing algorithms that employ the hop count based k-shortest link-disjoint paths as the predetermined routing paths. Our simulation results show that using the link-disjoint routing paths found by the proposed method yields significantly lower connection blocking probability than employing the hop count based k-shortest link-disjoint paths.